The colony currently maintains thirteen strains, most of which have diverged genetically from the stocks from which they were originally derived. These constitute animal models for the study of spontaneous and induced convulsion seizures; abnormally high aggression associated with genetic factors; variations in rate-limiting enzymes for several neural transmitters; differences in responses to early stress; differences in alcohol preference, tolerance and withdrawal syndromes; differences in longevity; and differences in sleep-wake and other activity patterns. A number of mutants arising on these backgrounds have also been detected and are in process of analyses. These provide models of single gene effects on neural processes and behavior. The SPF colony insures against the loss of these unique stocks as a result of disease, permits the collection of longevity data, and provides for controlled conditions of rearing that eliminates undetected stress factors resulting from intercurrent disease in conventional colonies. The research of those investigators using these stocks depends upon their continued availability, since the same results are not obtainable using strains from other sources. Work on the parameters mentioned will be continued. BIBLIOGRAPHIC REFERENCES: Yanai, J., P. Y. Sze and B. E. Ginsburg, 1975. Differential induction of behavioral and metabolic changes by ethanol during early development. Behav. Genet. 5:111-112 (abstract). Yanai, J., P. Y. Sze and B. E. Ginsburg, 1975. Effects of aminergic drugs and glutamic acids on audiogenic seizures induced by early exposure to ethanol. Epilepsia 16:67-71.